Parenthetical
The Parenthetical script element allows us to give direction to the actor where absolutely necessary. Use this sparingly (directors like to, well, direct) but know that it is available. Here's an example from Portals that (looking at it now) is perhaps not needed. Of course, he would be gasping if he just ran in from this sort of situation.
Here are two more ways we can use the Parenthetical element:
Note
Once more, in the modern spec script, do not use the Parenthetical element very much. Our next element, Shot, should not be used at all in a spec script—never ever.